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Blog Pick of the Month – April 2010

There were 34 blog posts covering PLoS ONE articles aggregated on ResearchBlogging.org in April. And as is now usual, it took me a lot of time and effort to narrow down the field and finally choose just one to pick. But pick I did….

Unlike the smaller and more vulnerable mammals, African elephants have relatively few predators that threaten their survival. The sound of disturbed African honeybees Apis meliffera scutellata causes African elephants Loxodonta africana to retreat and produce warning vocalizations that lead other elephants to join the flight. In our first experiment, audio playbacks of bee sounds induced elephants to retreat and elicited more head-shaking and dusting, reactive behaviors that may prevent bee stings, compared to white noise control playbacks. Most importantly, elephants produced distinctive “rumble” vocalizations in response to bee sounds. These rumbles exhibited an upward shift in the second formant location, which implies active vocal tract modulation, compared to rumbles made in response to white noise playbacks. In a second experiment, audio playbacks of these rumbles produced in response to bees elicited increased headshaking, and further and faster retreat behavior in other elephants, compared to control rumble playbacks with lower second formant frequencies. These responses to the bee rumble stimuli occurred in the absence of any bees or bee sounds. This suggests that these elephant rumbles may function as referential signals, in which a formant frequency shift alerts nearby elephants about an external threat, in this case, the threat of bees.

Why is this research important? Aside from the general importance of better understanding animal communication, as it can inform our understanding of human communication, this research has very practical implications as well. Elephants regularly raid the crops of humans; strategically placed beehives (or even just speakers broadcasting bee sounds or bee rumbles), could minimize human-elephant conflict and potential elephant deaths.

I am about to notify both Jason and the authors of the article and send them the famous PLoS ONE t-shirts as prizes. This month’s runners-up are Jeremy of Voltage Gate, Razib from Gene Expression and Jacqueline of the Laika’s MedLibLog.